Bearing wall of wooden house

ABSTRACT

A bearing wall partitions into a plurality of openings and in a vertical direction between adjacent column members by bridging a beam member that serves as a window sill between intermediate portions of the adjacent column members in a framework. Both end portions of the beam member are tied to intermediate portions of the adjacent column members via metal joints. A window is installed in the upper opening, and a peripheral end portion of the structural plywood is fixed to the lower opening with a nail. The structural plywood is fixed with nails at a rough nail pitch.

TECHNICAL FIELD

The present invention relates to a bearing wall of a wooden housecapable of maintaining satisfactory seismic resistance while allowinginstallation of a window.

BACKGROUND ART

In a wooden house, bearing walls are provided to meet the required wallquantity, so that the wooden house can withstand horizontal force duringan earthquake or a typhoon. This type of bearing wall is configured bybridging a brace over an opening between adjacent column members in aframework, or sticking a structural plywood so as to cover the entireopening between adjacent column members in a framework.

In general, it is impossible to attach a brace or a structural plywoodas described above in a part where a window is installed, it isdifficult to maintain satisfactory seismic resistance, and the wall isoften not accepted as a bearing wall. For this reason, installation of awindow may be restricted in order to meet the required wall quantity.

Therefore, in recent years, a bearing wall capable of maintainingsatisfactory seismic resistance while allowing installation of a windowhas been proposed as disclosed in Patent Literature 1, for example. Inthis bearing wall, an aseismic glass unit panel formed by integrating abase wood member and a glass plate with each other so that externalforce can be transmitted is attached to a window installation openingformed between adjacent column members in a framework so as to increasethe wall quantity with the in-plane rigidity of the glass plate, thatis, to cause the glass plate to function as a structural face plate, sothat satisfactory seismic resistance is maintained.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Application Laid-Open No.2009-293367

SUMMARY OF THE INVENTION Technical Problems

However, regarding the above bearing wall, a window to be installed inthe window installation opening is limited to a structure such as afixed window, for example, in which a base wood member and a glass plateare integrated with each other so that external force can betransmitted, it is difficult to install an openable window such as adouble sliding window, for example, and there is a problem that theversatility is poor.

An object of the present invention is to provide a bearing wall capableof solving the above problems and maintaining satisfactory seismicresistance while allowing installation of various windows.

Solutions to the Problems

To solve the above-mentioned problems, a bearing wall 1 according to thepresent invention partitions into a plurality of openings 13 and 14 in avertical direction between adjacent column members 3 by bridging atleast one beam member 11 that serves as a window lintel or a window sillbetween intermediate portions of the adjacent column members 3 in aframework 2 of the wooden house, and the bearing wall has a structuralplywood 50 stuck onto an opening 14 other than a window installationopening 13 among the openings 13 and 14, wherein both end portions ofthe beam member 11 are tied to intermediate portions of the adjacentcolumn members 3 via metal joints 20, and a peripheral end portion ofthe structural plywood 50 is fixed to the opening 14 with a nail or ascrew.

Specifically, the beam member 11 has a beam height of 150 mm and a beamwidth of 120 mm. In addition, a peripheral end portion of the structuralplywood 50 is fixed to the opening 14 with nails or screws by drivingnails or screws at a ratio of nine nails or screws per 1 m along aperipheral end portion of the structural plywood 50. Further, horizontalframe members 10 and 12 having a cross-sectional area smaller than across-sectional area of the beam member 11 are bridged between upper endportions or lower end portions of the adjacent column members 3, so thatthe horizontal frame members 10 and 12 serve as a base for installing awindow 40 or fixing the structural plywood 50 with nails or screws.

Advantageous Effects of Invention

In a bearing wall of the present invention, a beam member (structuralmaterial) is used as a window lintel or a window sill so that both endportions of the beam member are tied to intermediate portions ofadjacent column members in a framework via metal joints, and aperipheral end portion of a structural plywood is fixed to the openingwith nails or screws, and therefore the resistance to horizontal forceduring an earthquake or a typhoon can be increased, and satisfactoryseismic resistance can be maintained regardless of the type of window tobe installed in a window installation opening.

In particular, the cross-sectional area of the beam member is increased(beam height 150 mm×beam width 120 mm) so that the beam member itself orthe joint between the beam member and the column member becomes unlikelyto be destroyed, or the pitch of nails or screws for fixing a structuralplywood is made rough (a ratio of nine nails or screws per 1 m) toprevent excessive rise of the load imposed on the bearing wall so thatflexure fracture of the column member becomes unlikely to occur, and itis therefore possible to obtain a tenacious structure having deformationextensibility significantly improved.

Moreover, regarding a horizontal frame member bridged between upper endportions or lower end portions of adjacent column members, since largeforce is not likely to act and the possibility of fracture is low evenif horizontal force is applied during an earthquake or a typhoon, thecross-sectional area is made smaller than that of the beam member thatserves as the window lintel or the window sill, which makes it possibleto reduce the material cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a bearing wall in oneembodiment according to the present invention.

FIG. 2 is a perspective view of a bearing wall.

FIG. 3 is a front view showing a state that a window of a bearing walland the structural plywood are not installed.

FIG. 4A is an exploded perspective view showing a joint via the metaljoint of a beam member and a column member.

FIG. 4B is an erection perspective view showing a joint via the metaljoint of a beam member and a column member.

FIG. 5 is a view showing a shearing test result of a bearing wall.

FIG. 6 is a view showing a shearing test result of a bearing wall in thecomparative example.

FIG. 7 is a front view showing a state that a window and the structuralplywood of a bearing wall are not installed in the comparative example.

FIG. 8 is a front view showing a state that a window and the structuralplywood of a bearing wall are not installed according to anotherembodiment.

FIG. 9 is a front view showing a state that a window and the structuralplywood of a bearing wall are not installed according to anotherembodiment.

FIG. 10 is a front view showing a state that a window and the structuralplywood of a bearing wall are not installed according to anotherembodiment.

DESCRIPTION OF EMBODIMENTS

The following description will explain embodiments of the presentinvention in detail with reference to the drawings. As shown in FIGS. 1and 2, a bearing wall 1 of a wooden house according to an embodiment ofthe present invention is partitioned into two openings 13 and 14 in thevertical direction between adjacent column members 3 constituting aframework 2 by bridging a window lintel 10 as a horizontal frame memberbetween upper end portions of the adjacent column members 3 constitutingthe framework 2, bridging a beam member 11 that serves as a window sillbetween intermediate portions of the adjacent column members 3constituting the framework 2, and bridging a base member 12 as ahorizontal frame member between lower end portions of the adjacentcolumn members 3 constituting the framework 2. As shown in FIG. 3, it isto be noted that an upper end portion of each column member 3 is fixedto a beam member 4 constituting the framework 1 via a column head metalfitting 15, and a lower end portion of each column member 3 is fixed toa rising portion of a cloth foundation 5 via a column base metal fitting16.

The window lintel 10 is made of a square timber having a vertical crosssection height of 60 mm and a horizontal width of 120 mm, and both endportions thereof are fixed to upper end portions of the adjacent columnmembers 3 with nails or screws. Similar to the window lintel 10, thebase member 12 is made of a square timber having a vertical crosssection height of 60 mm and a horizontal width of 120 mm, and both endportions thereof are fixed to lower end portions of the adjacent columnmembers 3 with nails or screws. On the other hand, the beam member 11that serves as a window sill is made of a square timber having avertical cross section height (beam height) of 150 mm and a horizontalwidth (beam width) of 120 mm, and both end portions thereof are tied tointermediate portions of the adjacent column members 3 via metal joints20.

As shown in FIGS. 4A and 4B, each metal joint 20 includes a plate-shapedcolumn-side fixing portion 23 formed by bending a metal plate into aU-shape in a plan view, and a pair of right and left plate-shapedbeam-side fixing portions 24 protruding from both end portions in thevertical direction of the column-side fixing portion 23. A plurality ofbolt insertion holes 25 are formed at the column-side fixing portion 23at an interval in the vertical direction. At each beam-side fixingportion 24, a substantially V-shaped pin receiving groove 26 that opensupward, and a pin insertion hole 27 are formed at an interval in thevertical direction.

The column members 3 and the beam member 11 that serves as a window sillare tied using the metal joints 20 as follows. It is to be noted that apair of bolt through holes 30 are formed at an intermediate portion ofeach column member 3 at an interval in the vertical direction. At an endportion of the beam member 11, a pair of slits 31 that open to the upperand lower surfaces and the end surface of the beam member are formed atan interval in the lateral direction. Furthermore, a pair of pin throughholes 32 are formed at an end portion of the beam member 11 at aninterval in the vertical direction so as to be orthogonal to the slit31.

First, the column-side fixing portion 23 of a metal joint 20 is broughtinto contact with an intermediate portion of a column member 3 so thatthe bolt insertion holes 25 are overlapped with the bolt through holes30 of the column member 3. From this state, bolts 35 are inserted intothe bolt through holes 30 and the bolt insertion holes 25 thatcorrespond to each other, and nuts 36 are screwed into tip portions ofthe bolts 35 and tightened to fix the column-side fixing portion 23 of ametal joint 20 to an intermediate portion of the column member 3. Then,an end portion of the beam member 11 is brought into contact with anintermediate portion of the column member 3 by inserting the beam-sidefixing portions 24 of the metal joint 20 into the slits 31. At thistime, a drift pin 37 is inserted into an upper pin through hole 32 ofthe beam member 11 in advance, and the drift pin 37 is dropped into thepin receiving grooves 26 of the beam-side fixing portions 24 so as totemporarily fix the beam member 11 to the beam-side fixing portions 24so that a lower pin through hole 32 of the beam member 11 and the pininsertion holes 27 of the beam-side fixing portions 24 correspond toeach other. From this state, an end portion of the beam member 11 isfixed to the beam-side fixing portions 24 of the metal joint 20 byinserting a drift pin 37 into the pin through hole 32 and the pininsertion holes 27 that correspond to each other. As a result, theintermediate portion of the column member 3 and the end portion of thebeam member 11 are tied to each other via the metal joint 20.

As shown in FIGS. 1 and 3, the upper opening 13 is constituted of asquare frame-shaped portion surrounded by the adjacent column members 3,the window lintel 10, and the beam member 11 that serves as a windowsill, and a window 40 is installed in the upper opening 13. That is, theupper opening 13 serves as a window installation opening.

As shown in FIGS. 1 and 2, the window 40 is a double sliding window inwhich a pair of paper sliding doors 42 are slidably attached to a windowframe 41, and is fitted into the window installation opening 13 andinstalled by fixing with nails or screws. It is to be noted that thewindow 40 is not limited to a double sliding window, and may be any kindof window such as a fixed window, a sash window, an outward openingwindow, a folding window, and a bay window.

As shown in FIGS. 1 and 3, the lower opening 14 is constituted of asquare frame-shaped portion surrounded by the adjacent column members 3,the beam member 11 that serves as a window sill, and the base member 12,a half column 45 and studs 46 are extended between the beam member 11and the base member 12 in the lower opening 14, and a square structuralplywood 50 is stuck. Although upper and lower end portions of the halfcolumn 45 and the studs 46 are fixed to the beam member 11 and the basemember 12 with nails or screws, it is to be noted that the upper andlower end portions may be fixed via metal joints.

The structural plywood 50 is fixed to the lower opening 14, that is, theadjacent column members 3, the beam member 11 that serves as a windowsill, and the base member 12 with nails by driving nails 51 at a ratioof nine nails per 1 m (a pitch of approximately 120 mm) along aperipheral end portion thereof. Moreover, nails 51 are appropriatelydriven also into portions of the structural plywood 50 with which thehalf column 45 or the studs 46 come into contact, and fixing to the halfcolumn 45 or the studs 46 with nails is also achieved. It is to be notedthat a small gap 47 is provided between the beam member 4 and the windowlintel 10 constituting the framework 2, and a strip-shaped plywood 52 islaid across the beam member 4 and the window lintel 10 and fixed withnails so as to close the gap 47.

As described above, since the beam member 11 that is a structuralmaterial having a large cross-sectional area is used as a window sill,and both end portions of the beam member 11 are tied with intermediateportions of the adjacent column members 3 in the framework 2 via themetal joints 20, fracture of the beam member 11 itself or the jointsbetween the beam member 11 and the column members 3 are less likely tooccur in the above bearing wall 1. Moreover, since the structuralplywood 50 is fixed to the lower opening 14 with nails at a rough nailpitch (at a pitch of approximately 120 mm), it is possible to preventexcessive rise of the load imposed on the bearing wall 1 to reduce thebending load of the column member 3 (to prevent excessive force fromacting from the joints between the beam member 11 and the column members3 to the intermediate portion of the column members 3), and to increasethe resistance to horizontal force during an earthquake or a typhoonwhile preventing flexure fracture of the column members 3. As a result,a tenacious structure having deformation extensibility significantlyimproved is obtained, and satisfactory seismic resistance can bemaintained.

Moreover, regarding the window lintel 10 and the base member 12 ashorizontal frame members bridged between upper and lower end portions ofthe adjacent column members 3, since large force is not likely to actand the possibility of fracture is low even when horizontal force isapplied during an earthquake or a typhoon, the cross-sectional area ismade smaller than that of the beam member 11 that serves as a windowsill, which makes it possible to reduce the material cost.

Although not shown in the figures, it is to be noted that the abovebearing wall 1 is provided with an interior material stuck onto theindoor side thereof and an exterior material stuck onto the outdoor sidethereof, except for the part where the window 40 is installed.

FIG. 5 shows a shearing test result of the above bearing wall 1, andFIG. 6 shows a shearing test result of a bearing wall of a comparativeexample. As shown in FIG. 7, in a bearing wall of the comparativeexample, it is to be noted that a window sill 11A is made of a squaretimber having a vertical cross section height (beam height) of 60 mm anda horizontal width (beam width) of 120 mm, both end portions thereof arefixed to intermediate portions of adjacent column members 3 with nails,and a structural plywood is fixed to a lower opening 14 with nails bydriving the nails at a pitch of approximately 60 mm along the peripheralend portion thereof. The other configurations are similar to those ofthe above bearing wall 1. In the shearing test, a load in the horizontaldirection was applied to the beam member 4 constituting the framework 2,and the deformation angle with respect to the load at this time wasmeasured. This measurement was performed three times each.

It was confirmed from this shearing test result that, in the abovebearing wall 1, the maximum load was suppressed, the wall was tenaciousenough not to break until large deformation occurs, and a sufficientshort-term allowable shearing strength could be secured, while, in thecomparative example, the maximum load increased, deformation did notextend, brittle fracture occurred, and the short-term allowable shearingstrength significantly lowered. It is to be noted that the short-termallowable shearing strength is found from the minimum value of yieldload (Py), ultimate load and deformation performance (Pux0.2/Ds), ⅔ ofmaximum load (⅔xPmax), and load at deformation angle 1/120.

FIGS. 8 to 10 show bearing walls 1 according to other embodiments. Abearing wall 1 shown in FIG. 8 is partitioned into two openings 60 and61 in the vertical direction between adjacent column members 3 bybridging a beam member 11 that serves as a window lintel betweenintermediate portions of the adjacent column members 3 constituting aframework 2. In addition, a half column 45 and studs 46 are extendedbetween the beam member 4 constituting the framework 1 and the beammember 11 that serves as a window lintel in the upper opening 60, asquare structural plywood 50 is stuck, and a window 40 is installed inthe lower opening 61. It is to be noted that the other configurationsare similar to those of the above bearing wall 1.

A bearing wall 1 shown in FIG. 9 is partitioned into three openings 62,63, and 64 in the vertical direction between adjacent column members 3by bridging a window lintel 10 as a horizontal frame member betweenupper end portions of the adjacent column members 3 constituting aframework 2, and bridging two beam members 11 that serves as a windowlintel and a window sill between intermediate portions of the adjacentcolumn members 3 constituting the framework 2. A half column 45 andstuds 46 are extended between the upper and lower beam members 11 in theintermediate opening 63, a square structural plywood 50 is stuck, and awindow 40 is installed in the upper opening 62 and the lower opening 64.It is to be noted that the other configurations are similar to those ofthe above bearing wall 1.

A bearing wall 1 shown in FIG. 10 is partitioned into three openings 65,66, and 67 in the vertical direction between adjacent column members 3by bridging two beam members 11 that serve as a window lintel and awindow sill between intermediate portions of the adjacent column members3 constituting a framework 2 and by bridging a base member 12 as ahorizontal frame member between lower end portions of the adjacentcolumn members 3 constituting the framework 2. In addition, in the upperopening 65, a half column 45 and studs 46 are extended between the beammember 4 constituting the framework 1 and the beam member 11 that servesas a window lintel, and a square structural plywood 50 is stuck. In thelower opening 67, a half column 45 and studs 46 are extended between thebeam member 11 and the base member 12 that serves as a window sill, anda square structural plywood 50 is stuck. In the intermediate opening 66,a window 40 is installed. It is to be noted that the otherconfigurations are similar to those of the above bearing wall 1.

Similar to the above bearing wall 1, each of the bearing walls 1 shownin FIGS. 8 to 10 also has a tenacious structure having deformationextensibility significantly improved, and can maintain satisfactoryseismic resistance.

Although embodiments of the present invention have been explained above,the invention is not limited to the above embodiments, and variousmodifications can be made within the scope of the invention. Forexample, a bearing wall of the present invention is not limited to abearing wall to be provided on the first floor foundation of a woodenhouse as described in the above embodiments, and may be provided on anupper floor of a wooden house. In this case, for example, adjacentcolumn members constituting a framework are laid across upper and lowerbeam members constituting the framework. Moreover, for sticking astructural plywood onto an opening, not only fixing with nails but alsofixing with screws may be employed.

DESCRIPTION OF REFERENCE SIGNS

-   1 bearing wall-   2 framework-   3 column member-   11 beam member-   10,12 horizontal frame member-   13,61,62,64,66 window installation opening-   14,60,63,65,67 opening for sticking the structural plywood-   20 metal joint-   40 window-   50 structural plywood-   51 nail

1. A bearing wall (1) of a wooden house partitioned into a plurality of openings (13) and (14) in a vertical direction between adjacent column members (3) by bridging at least one beam member (11) that serves as a window lintel or a window sill between intermediate portions of the adjacent column members (3) in a framework (2) of the wooden house, the bearing wall having a structural plywood (50) stuck onto an opening (14) other than a window installation opening (13) among the openings (13) and (14), wherein both end portions of the beam member (11) are tied to intermediate portions of the adjacent column members (3) via metal joints (20), and a peripheral end portion of the structural plywood (50) is fixed to the opening (14) with a nail or a screw.
 2. The bearing wall of a wooden house according to claim 1, wherein the beam member (11) has a beam height of 150 mm and a beam width of 120 mm.
 3. The bearing wall of a wooden house according to claim 2, wherein a peripheral end portion of the structural plywood (50) is fixed to the opening (14) with nails or screws by driving nails or screws at a ratio of nine nails or screws per 1 m along a peripheral end portion of the structural plywood (50).
 4. The bearing wall of a wooden house according to claim 3, wherein horizontal frame members (10) and (12) having a cross-sectional area smaller than a cross-sectional area of the beam member (11) are bridged between upper end portions or lower end portions of the adjacent column members (3), so that the horizontal frame members (10) and (12) serve as a base for installing a window (40) or fixing the structural plywood (50) with nails or screws. 